Intraocular Lens Master Research Articles

Parsiyel Koherens İnterferometri ve Çift Scheimflug Tabanlı İki Ayrı Biometri ile Ölçülen Göz İçi Lens Sonuçlarının Karşılaştırılması

Objective: To compare the biometric values measured by Dual Scheimpflug-based and partial coherence interferometry-based optic biometers and to evaluate the intraocular lens (IOL) power calculations performed by using different formulas including SRK-2, SRK-T, Holladay 1 and Hoffer Q. Material and Methods: Patients who applied to our clinic with visual impairment and diagnosed as senil cataract were recruited in the current study. After detailed ophthalmologic examination, biometric measurements including mean anterior chamber depth (ACD), axial length (AL) and keratometric parameters (K1, K2) were performed by using the Galilei G6 Dual Scheimpflug Analyzer and IOL Master 500. The IOL power (Sensar AAB00 hydrophobic acrylic IOL AMO) calculations targeting emmetropia were performed by using SRK-2, SRK-T, Holladay 1 and Hoffer Q formulas with the two devices. These parameters were compared with statistical analysis. Results: One hundred and six eyes of 94 patients with nuclear sclerosis were recruited. The mean age of patients (40 female, 54 male) was 67.44±8.99 years. The value of K1 was found to be statistically higher in measurement performed by IOL Master 500 (p<0.001). The IOL power was calculated statistically higher with all formulas measured by IOL Master 500 (p<0.001). Conclusion: The mean ACD, AL and K2 values did not differ between the two devices. Average K and K1 parameter was measured higher when measured with IOL Master 500. The mean IOL power was calculated statistically significantly different between these two devices.

Comparison of accuracy between ultrasound B scan and partial coherence interferometry (IOL master) in IOL (intraocular lens) power calculation

Aims and Objectives: To compare the accuracy of ultrasound A scan biometry and IOL master (PCI) biometry in intraocular power calculation, by doing a comparative study of difference in biometry by conventional methods and optical biometry (IOL master). Materials and Methods: Place of study: Aravind Eye Hospital, India. Design of Study: Prospective, non randomised, clinical study. Study Group and Duration: The study involves patients who underwent cataract surgeries at Aravind Eye Hospital, Tirunelveli during the specified time period. The IOL power and predicted refractive outcome were calculated for every patient by both the methods, A scan ultrasound Biometry IOL master (Partial Coherence interferometry) Inclusion Criteria: Only those patients in whom it was possible to secure a reliable IOL master reading (on the basis of good SNR), were included. Results: In a 12 month period, 337 eyes were consecutively enrolled in the study. Both ultrasound A scan and partial coherence interferometry was performed and IOL power implanted as per the IOL master. Inclusion criterion and exclusion criterion used as mentioned. The difference in between the final and predicted refraction is compared for both the groups. The overall Mean absolute error was 0.402 ± 0.407 with the ultrasound A scan & 0.388 ± 0.406 for the IOL master, with the probability value (p-value) 0.3802. The mean numerical error (the difference between the refractive outcome and the predicted spherical equivalent) is -0.226 ± 0.526 (min -2.66 & max 2.06) for the ultrasound scan group and -0.217 ± 0.518 (min -2.41 & max 2.10) for the IOL master group, with the probability value (p-value) being 0.514. We got a comparative result in our study, though not significant, but it is more in favour of IOL master (PCI) as per the mean absolute error and mean numerical error calculations. When analysing the Mean Axial Length readings, the findings were almost similar, with an insignificant p-value. Keywords: Biometry

Comparison of Ocular Biometry Profiles in Urban and Rural Cataract Candidates in Eastern China.

Purpose To compare ocular biometric parameters between urban and rural cataract patients in Shanghai, China. Methods A study of ocular biometry records from urban and rural hospitals was performed for cataract patients at least 50 years of age. The ocular biometrical parameters, which were measured with partial coherence laser interferometry (IOL Master, Zeiss), were axial length (AL), anterior chamber depth (ACD), radius of corneal curvature (K, including steep/flat/average K), astigmatism, and axis. Only the right eye record of each patient was analysed. Results Ocular biometric data included 2839 urban patients (73.15 ± 9.54 years) and 2646 rural patients (73.64 ± 7.32 years). Mean AL, ACD, and K were 24.35 ± 2.34 mm, 3.14 ± 0.58 mm, and 44.38 ± 1.52 D, respectively, in urban patients and 23.58 ± 1.70 mm, 3.08 ± 0.57 mm, and 44.53 ± 1.50 D, respectively, in rural patients. The urban subjects had significantly longer axial lengths (in both univariate and multivariate linear regression analyses) and deeper ACDs (in univariate analysis) than rural subjects (p < 0.01). There was no significant difference in steep K, flat K, and average K between the two groups. With-the-rule (WTR) corneal astigmatism was found in 1787 eyes (32.58%), against-the-rule (ATR) corneal astigmatism was found in 2727 eyes (49.72%), and oblique corneal astigmatism was found in 971 eyes (17.70%). Conclusions We report biometry and astigmatism data in a large cohort of urban and rural adult subjects for the first time. In our study, a short AL, shallow ACD, and axis turned in an ATR direction had higher prevalence rates in the rural subjects. This profile of ocular biometric data and corneal astigmatism will be helpful in planning for intraocular lens (IOL) power calculations and astigmatism correction in subjects in different locations.

Clinical Outcomes of the Scleral Fixation of Posterior Chamber Intraocular Lens using the Modified Yamane's Technique: a Swept-source Optical Coherence Tomography Study

To observe the postoperative outcomes of the scleral fixation of posterior chamber intraocular lens (SF-PCIOL) using the modified Yamane's technique with the aid of swept-source optical coherence tomography (SS-OCT). Prospective observational case series. This study involved 20 patients who underwent SF-PCIOL with the modified Yamane's technique, from December 2017 to November 2019. All patients had routine preoperative examinations, including biometric measurement by IOL master, measurements of uncorrected distance visual acuity (UDVA) and best corrected distance visual acuity (BCDVA). The SRK/T formula was used to calculate the power of intraocular lens (IOL). After the surgery, UDVA and intraocular pressure were evaluated for 1 d, UDVA, BCDVA, spherical equivalent (SE) and corneal endothelial cell density were measured for 1 week, 1 month, 3 and 6 months, respectively. The IOL tilt and the symmetry of hepatitis in the scleral tunnel were measured by SS-OCT. The mean follow-up duration was (7.20±6.56) months (range, 3-26 months). The mean preoperative UDVA was (1.70±0.38) LogMAR, and it improved to (0.48±0.50) LogMAR ( P=0.001). There was no statistically significant difference between the pre- and post-operative BCDVA, i.e. (0.44±0.50) LogMAR and (0.32±0.48) LogMAR, respectively ( P=0.08). The mean spherical equivalent was (-0.53±0.86) diopter (D) and the postoperative refractive error was (0.27±0.82) D. Seventeen patients underwent SS-OCT examinations. The mean IOL tilt was (3.28±3.00)°. There was no significant difference between the horizontal and vertical tilt ( P=0.326). The IOL tilt did not show a significant correlation with spherical and cylindrical refractive error ( P=0.532, P=0.241). There was no statistically significant difference in the HL (the length of haptics fixed in the scleral tunnel) of nasal and temporal haptic, which were (2.24±0.20) mm and (2.17±0.23) mm, respectively ( P=0.193). And there were no statistically significant differences between the HD (the distance between the center of haptic flange and scleral spur) of nasal and temporal haptic, (1.58±0.07) mm and (1.66±0.08) mm, respectively ( P=0.338). The changes of IOL haptics in the scleral tunnel were tracked by 10 patients. The HL (nasal: HL-N; temporal: HL-T) and the HD (nasal: HD-N; temporal: HD-T) of haptics in the tunnel were measured and recorded at three time points, including 1 week, 1 and 3 months after surgery. There was no significant difference in HL-N, HL-T, HD-N and HD-T at the three time points ( P=0.931, P=0.091, P=0.175, and P=0.505, respectively). All patients underwent uneventful surgery. The postoperative complications included transient corneal edema in 6 eyes, transient IOP elevation in 3 eyes, vitreous hemorrhage in 1 eye, cystoid macular edema in 2 eyes, and macular hole in 1 eye. The SF-PCIOL using modified Yamane's technique, is capable of producing satisfactory and consistent postoperative outcomes for patients with few postoperative complications. SS-OCT is a powerful tool for measuring optic tilt and the IOL hepatic symmetry in scleral tunnel.

Comparison of the accuracy of 11 intraocular lens power calculation formulas.

To compare the accuracy of 11 intraocular lens (IOL) power calculation formulas (SRK-T, Hoffer Q, Holladay I, Haigis, Holladay II, Olsen, Barrett Universal II, Hill-RBF, Ladas Super formula, EVO and Kane). Private university hospital (QuironSalud, Madrid, Spain). Retrospective case series. Data were compiled from 481 eyes of 481 patients who had undergone uneventful cataract surgery with IOL insertion. Preoperative biometric measurements were made using an IOL Master® 700. Respective ULIB IOL constants (http://ocusoft.de/ulib/c1.htm) for each of 4 IOL models implanted were used to calculate the predictive refractive outcome for each formula. This was compared with the actual refractive outcome determined 3 months postoperatively. The primary outcome was mean absolute prediction error (MAE). The study sample was divided according to axial length (AL) into three groups of eyes: short (⩽22.00 mm), normal (22.00-25.00 mm) and long (⩾25.00 mm). The Barrett Universal II and Haigis formulas yielded the lowest MAEs over the entire AL range (p < .01, except EVO) as well as in the long (p < .01, all formulas) and normal (p < .01, except Haigis, Holladay II, Olsen and LSF) eyes. In the short eyes, the lower MAEs were provided by Haigis and EVO (p < .01 except Hoffer Q, SRK/T and Holladay I). Barrett Universal II was the most accurate for IOL power calculation in the normal and long eyes. For short eyes, the formulas Haigis and EVO seem best at predicting refractive outcomes.

Ophthalmic changes in patients with hemifacial atrophy (Parry-Romberg syndrome).

Parry-Romberg syndrome (PRS) is a rare condition characterized by progressive, unilateral facial atrophy. We hypothesize that patients with this condition may have involvement of the ocular structures. Here, we report our ophthalmic, clinical and anatomical findings in an observational study of six patients with long-standing PRS. Patients diagnosed with PRS were invited to participate in a clinic visit during which the following tests were administered and data recorded: best-corrected vision, refractive error, Ishihara color plates, Hertel exophthalmometry, gonioscopy, complete slit-lamp and dilated fundus examination, Intra Ocular Lens Master measurements and keratometry. Two-sample T tests were used to compare data between affected and unaffected eyes, as well as affected eyes and a normative population. Six patients underwent complete eye examinations. The mean spherical equivalent of the affected eye was + 3.83D, while that of the unaffected eye was + 0.13D. The atrophic hemiface averaged 2.8mm of enophthalmos on Hertel exophthalmometry. The axial length of the atrophic eye was 0.91mm shorter than the unaffected eye. Compared to normative data, in patients with PRS, the difference between eyes was statistically different for each of the following variables: visual acuity, spherical equivalent, corneal diameter, axial length and flat and steep keratometry. This is one of the first quantitative, exploratory studies with ophthalmic measurements in patients with PRS. Our results suggest the globe may demonstrate atrophic changes similar to other soft tissues in the face known to be affected by this condition.

Optical Biometry Versus Ultrasound Biometry

Background: Implantation of an intraocular lens (IOL) is the gold standard in modern-day cataract surgery. Over the last decade, IOL power calculations have become a focal point of cataract surgery. Objective: To compare the sensitivity and specification of optical biometry and applanation ultrasound biometry in the measurement of intraocular lens. Patient and methods: This prospective cohort study was done on 100 eyes from one hundred patients undergoing phacoemulsification with primary intraocular lens implantation. and scheduled for cataract surgery in the Ophthalmology Department of Menoufia University Hospitals and El-Mahalla Ophthalmology Hospital. Fifty eyes of patients were measured by ultrasound measurement (by A-Scan, Group 1) and the other 50 eyes by optical biometry (by IOL Master, Group 2). Result: in Group 1There were 22 eyes of 22males (44%), and 28 eyes of 28 females (56%) with a mean age was 58.4 ±10.13years. While, in Group 2, there were 16 eyes of 16 males (32%), and 34 eyes of thirty-fourth females (68%) and the mean age of the patients in this group was 61.2±9.25 years. The mean IOL of the patient in Group I was (18.86±2.57) with minimum IOL power (16.29) and maximum IOL power (21.43). Whereas, the mean IOL potent ion of the patient in group II was (20.5±1.98) with minimum IOL power (18.52) and maximum IOL power (+22.48). Conclusion: We can conclude that IOL measurements performed by using the Zeiss IOL Master, using partial coherence interferometry, resulted that a significantly better IOL power forecast and therefore the refractive result in cataract surgery than Applanation US biometry.

Evaluation of corneal endothelial changes after posterior capsule rupture during phacoemulsification using specular microscope

Background Phacoemulsification cataract surgery is now the technique of choice for routine cataract extraction. However, posterior capsule rupture (PCR) during phacoemulsification cataract surgery remains an important complication because it may lead to poor visual outcome. Objective The aim of this study was to evaluate the effect of PCR during cataract extraction by phacoemulsification on the corneal endothelium using a specular microscope. Patients and methods A total of 50 patients with age range between 45 and 65 years were enrolled in this study during a period of 1 year. Anterior chamber depth measurement was done. Preoperatively, anterior chamber depth (mm) was recorded using intraocular lens master. Central corneal thickness (CCT) and the endothelial cell counts were measured using a noncontact specular microscope preoperatively and postoperatively. Results We compared the preoperative details and contrasted the 1- and 3-month postoperative outcomes, including best -corrected visual acuity, endothelial cell loss, CCT, coefficient of variation, and hexagonality. We found that the majority of our patients (92%) experienced improved best-corrected visual acuity at 3 months after phacoemulsification. Our patients had an increased CCT 1 month postoperatively, with a significant rise from baseline. When polymegathism was evaluated, we observed that coefficient of variation increased significantly from baseline, and declined slightly by 3 months postoperatively. Regarding cell count density, we observed a significant decrease of cell density following the operation after 1 month and a much more decrease after 3 months. Conclusion We concluded that PCR during phacoemulsification resulted in significant corneal endothelial damage; however, it provided better visual acuity. For better outcomes, early recognition of PCR is advised, besides immediate proper management to minimize the endothelial damage.

Accuracy of eight intraocular lens power calculation formulas for segmented multifocal intraocular lens.

To evaluate the accuracy of eight different intraocular lens (IOL) power calculation formulas for a segmented multifocal IOL. A total of 53 eyes of 41 adult cataract patients who underwent phacoemulsification and implantation with the SBL-3 segmented multifocal IOL between January 1, 2017 and January 31, 2019 were included in this retrospective study. Preoperative biometry measurements were obtained using an IOL Master. Manifest refraction was performed at least 4wk postoperatively. Accuracy of the eight formulas [Barrett Universal II, Emmetropia Verifying Optical (EVO), Haigis, Hill-RBF 2.0, Hoffer Q, Holladay 1, Kane, and SRK/T] was analyzed. Using current lens constants, all formulas exhibited errors of slight myopic shift in refractive prediction. The Barrett Universal II formula had a significantly lower median absolute error (MedAE) than did Holladay 1 (P=0.02), Kane (P=0.001) and Hill-RBF 2.0 (P<0.001) formulas. The Haigis formula had a lower MedAE value than did the Hill-RBF 2.0 formula (P=0.005). Differences in MedAE values among SRK/T, EVO and Hoffer Q formulas were not significant. After optimizing lens constants, the MedAE values of all formulas were reduced; significant changes were noted for EVO (P=0.022), Haigis (P=0.048), Hill-RBF 2.0 (P=0.014), Holladay 1 (P=0.045) and Kane (P=0.022) formulas. All formulas performed equally well after optimization of lens constants (P=0.203). All eight formulas tend to result in a myopic shift when using current lens constants. Optimized lens constants improve the accuracy of these formulas among adult Chinese patients.

Comparison of keratometry readings and corneal astigmatism obtained with Verion image-guided system, Pentacam, and intraocular lens Master in patients undergoing toric intraocular lens implantation

Comparison of keratometry readings and corneal astigmatism obtained with Verion image-guided system, Pentacam, and intraocular lens Master in patients undergoing toric intraocular lens implantation

Determinants of intraocular lens tilt and decentration after cataract surgery.

BackgroundTo identify the main determinants of intraocular lens (IOL) tilt and decentration after cataract surgery using a novel anterior segment optical coherence tomography (AS-OCT) method.MethodsFifty-six patients who underwent phacoemulsification with IOL implantation in one eye were continuously enrolled in this cohort study. Axial length (AL) was measured with IOL Master 700. The tilt and decentration of patients’ preoperative crystalline lenses and postoperative IOLs, as well as crystalline lens thickness (LT), were measured using AS-OCT before surgery and 1 week after surgery.ResultsThe mean tilt and decentration of the patients’ preoperative crystalline lenses were 4.90°±1.81° and 0.21±0.02 mm, and the mean tilt and decentration of IOLs were 4.75°±1.66° and 0.21±0.02 mm, respectively. There were no significant differences in magnitude, direction of tilt, or decentration between crystalline lenses and IOLs. The strongest determinant of IOL tilt was preoperative crystalline lens tilt (R2=0.512, P<0.001), followed by AL (R2=0.154, P=0.003). Additionally, crystalline lens decentration and AL explained 54.6% of the variability in IOL decentration. AL was the factor most highly associated with IOL decentration (R2=0.332, P<0.001), rather than crystalline lens decentration (R2=0.214, P<0.001).ConclusionsThe position of the preoperative crystalline lens and AL were the critical determinants of IOL tilt and decentration. The tilt and decentration of IOLs will be greater in patients with larger tilt and decentration of crystalline lenses, or shorter and longer AL.

Influence of pupil dilation on the Barrett universal II (new generation), Haigis (4th generation), and SRK/T (3rd generation) intraocular lens calculation formulas: a retrospective study

BackgroundDespite the surge in the number of cataract surgeries, there is limited information available regarding the influence of pupil dilation on predicted postoperative refraction and its comparison with recommended various intraocular lens power calculated using the different parameters. We used three different IOL power calculation formulas: Barrett Universal II (Barrett) (5-variable formula), Haigis (3-variable formula), and SRK/T (2-variable formula), in order to investigate the potential effect of pupil dilation on the predicted postoperative refraction (PPR) and recommended intraocular lens (IOL) power calculation.MethodsThis retrospective study included 150 eyes. All variables were measured and calculated using a ZEISS IOL Master 700. The following variables were measured before and after dilation: anterior chamber depth (ACD), lens thickness (LT), white-to-white (WTW). PPR and recommended IOL power were calculated by Barrett, Haigis, and SRK/T IOL calculation formulas. The change in each variable before and after dilation, and the correlations between all changes were analyzed using the Wilcoxon signed-rank test and the Spearman’s rank-order correlation test, respectively.ResultsThe mean absolute change (MAC) in PPR before and after dilation was found to be highest in the Barrett formula. Significant differences were found between each MAC (P < 0.0001). Significant changes were observed before and after dilation in ACD and LT (P < 0.0001), but not in WTW. Using the Barrett and Haigis formulas, there was a significant positive correlation between the change in PPR and change in ACD (P < 0.0001), and a negative correlation between change in PPR and change in LT (P < 0.0001). The correlations were strongest with the Barret formula followed by the Haigis, particularly in terms of LT. Changes in PPR determined by the Barrett formula also demonstrated a significant positive correlation with changes in WTW (P = 0.022). The recommended IOL power determined using Barrett and Haigis changed before and after dilation in 23.3 and 19.3% cases respectively, while SRK/T showed no change.ConclusionsIn terms of PPR and recommended IOL power, pupil dilation influenced mostly the Barrett formula. Given the stronger correlation between the changes in PPR when using Barrett and the changes in ACD, LT, and WTW, changes in ACD, LT, and WTW significantly affect how dilation influences the Barrett formula. Determining how dilation influences each formula and other variables is key to improving the accuracy of IOL calculations.

Intraocular lens Master optical biometry vs conventional ultrasonic biometry in intraocular lens power calculations in highly myopic vs emmetropic eyes

Aim The aim was to compare between the preoperative intraocular lens (IOL) power calculations accuracy measured by IOL Master vs applanation ultrasonic biometry in highly myopic and emmetropic eyes regarding postoperative refractive error. Patients and methods The IOL powers of 32 eyes of 32 patients prepared for phacoemulsification with IOL implantation were calculated preoperatively by IOL Master and A-scan. Postoperative refractive outcomes and spherical equivalent were compared with the predicted refractive error of each method. Results The mean±SD age of the 32 recruited patients was 53.91±10.21 years. The mean axial length (AXL) measured by IOL Master was higher (25.8±2.65 mm) than that with A-scan (25.46±3.43 mm), with a mean difference of 0.34±1.04 mm (P=0.2112). The mean predicted IOL power was 13.50±7.80 D with IOL Master vs 13.63±9.05 D with A-scan (P=0.930). However, no statistically significant difference was found regarding average K readings and predicted postoperative refraction (P=0.05 and 0.564, respectively). Further subgroup analysis revealed a statistically significant difference in AXL between both devices only in emmetropic group, with mean difference of 0.99±0.485 mm (P=0.00068). The mean absolute errors measured by IOL Master was 0.19±0.1417, whereas that of A-scan was 0.561±0.623. The mean difference between the two methods was −0.371 (P=0.0385), which was statistically significant. Discussion and conclusion The IOL Master AXL measurements were accurate, allowing more accurate calculation of the (IOL) power. It is user friendly, fast, with no contact with the corneal surface and with no possibility of damage to the surface or transmitting a disease.

Comparison of toric intraocular lens calculation using the new corneal curvature measurement methods and the haigis suite, barrett tk, barrett toric, and z calc formulas

Background: More than 50% of patients undergoing cataract surgery have corneal astigmatism ≥ 0.75 diopters (D). A fundamental factor for the calculation of the intraocular lens (IOL) is the power of corneal refraction, which can be calculated with different methods and incorporated into different mathematical prediction models. Little information has been written comparing new formulas that take into account posterior keratometry. Aims and Objectives: Compare the prediction of the ideal IOL with different formulas that use anterior keratometry and posterior keratometry measured by different devices. Setting: Private practice, Guadalajara, Jalisco, Mexico. Materials and Methods: A descriptive, observational and retrospective study was carried out where 50 healthy eyes with cataract and a degree of corneal astigmatism >1 D were evaluated, IOL calculation was compared using the anterior and total keratometries measured with the Zeiss IOL master 700 and the total corneal refractive power (TCRP) keratometries of the Oculus Pentacam. The results were also compared with the Haigis Suite, Barrett TK and Z Calc formulas. The IOL used for the analysis was the Zeiss AT TORBI 709M/MP. Results: It was found that the different formulas can generate different predictions in the cylinder power but no significant differences in the sphere power. Measurement of the posterior cornea did not significantly change the selection of the ideal IOL for implantation. Calculations with Haigis Suite and Z Calc are very similar. Barrett TK-Toric uses less cylindrical power than Haigis Suite and Z calc, regardless of the method chosen to measure corneal power. Conclusion: Our results contribute to clarify the current scenario where the great variety of options for the calculation of IOL generates uncertainty about which method generates better results of postoperative refraction.

Anterior chamber depth \u2014 a predictor of refractive outcomes after age-related cataract surgery

BackgroundAnterior chamber depth (ACD) is becoming a hot topic and plays an important role in correcting the refractive errors (REs) after cataract surgery. The aim of this study was to assess the ACD changes and their relationship with the REs after phacoemulsification and intraocular lens (IOL) implantation in patients with age-related cataracts.MethodsOne hundred forty-five eyes of 125 age-related cataract patients from the Department of Ophthalmology, Tangdu Hospital, China, were recruited. IOL Master was used for axial length (AL) and the IOL power calculation measurements, and the Pentacam HR device was used for the ACD and lens thickness (LT) measurements. Every patient underwent uncomplicated phacoemulsification by a single surgeon using a single technique. Postoperative refraction results were obtained at 1 month. The appropriate formula used for the IOL power calculation was chosen depending on the AL, specifically the Hoffer Q (AL < 22.0 mm), SRK/T (22.0 mm ≤ AL ≤ 30.0 mm), and Haigis (AL > 30.0 mm) formulas.ResultsThe postoperative ACD was deepened and tended to stabilize gradually after 2 weeks. A concurrent hyperopic shift (0.57 ± 0.47 D) was observed when the change in the ACD was less than 1.65 mm, whereas a myopic shift (− 0.18 ± 0.62 D) occurred contrarily, and the difference between the two groups was statistically significant (P < 0.0001). The change in ACD was significantly larger in the shallow anterior chamber (1.92 ± 0.40 mm) than in the deep chamber (1.33 ± 0.42 mm) (P < 0.0001). Similarly, the change in ACD was larger in the short AL (2.12 ± 0.37 mm) than in the long AL (1.32 ± 0.49 mm). The postoperative ACD and refractive changes were correlated with the preoperative ACD and AL (P < 0.0001), respectively. Two regression formulas were proposed: postoperative ACD = 3.524 + 0.294 × preoperative ACD and postoperative ACD = 3.361 + 0.228× (preoperative ACD + 1/2 LT).ConclusionsThe results of this study showed that the ACD deepened and was associated with a concurrent RE after cataract surgery. Postoperative changes in the ACD were related to the preoperative ACD and AL, which determined the refraction status and visual quality. The regression formula of the postoperative ACD could provide a theoretical basis for predicting refractive errors in the clinic.

Ocular biometry characteristics and corneal astigmatisms in cataract surgery candidates at a tertiary care center in North-East India.

Purpose:The purpose of this study is to determine the ocular biometry characteristics and corneal astigmatisms using partial coherence laser interferometry in patients aged 40 years or above undergoing cataract surgery in a medical college in North-East India.Methods:In a hospital-based cross-sectional study, ocular biometry characteristics such as axial length (AL), anterior chamber depth (ACD), white-to-white (WTW) diameter, corneal power (K), and corneal astigmatisms (D) of consecutive eligible cataract patients in a medical college in North-East India between January 2015 and December 2017 were determined using the intraocular lens (IOL) master. Height and weight were also measured.Results:A cross-sectional study evaluated ocular biometry characteristics of 641 eyes in 641 eligible patients. The mean age was 64.04 ± 10.81 years. The mean AL, ACD, WTW, corneal power, IOL power, and body mass index (BMI) were 23.34 ± 1.12 mm, 3.12 ± 0.39 mm, 11.92 ± 0.54 mm, 44.41 ± 1.50 diopter (D), 20.53 ± 2.79 D, and 26.12 ± 4.32, respectively. Against-the-rule, with-the-rule, and oblique astigmatisms were 48.4%, 33.2%, and 18.4%, respectively. Corneal astigmatism of ≥1 D was found in 292 eyes (45.55%) and >1.5 D in 182 eyes (28.39%). AL had statistically significant correlation with ACD, WTW, K, IOL power, height and weight but not with age. By multivariate analysis, AL was found to be associated with ACD, WTW, K and IOL power (P ≤ 0.05). The mean AL was negatively correlated with the mean K (R-square 0.138).Conclusion:This study is likely to provide the initial normative data for ocular biometry values in Indian adults 40 years or above, because such data is lacking in Indians using the IOL master. This will also help ophthalmologists in planning and improving the quality of surgical outcomes in phacoemulsification and phacorefractive surgeries by choosing the appropriate IOL and incision location.

Effects of anterior chamber depth and axial length on corneal endothelial cell density after phacoemulsification.

Objective:To evaluate mean decrease in Corneal Endothelial cell Density (CED) after phacoemulsification in patients with different Anterior Chamber Depths (ACDs) and Axial Lengths (ALs).Methods:This prospective stratified controlled study was conducted at PNS Shifa Hospital, Karachi. One hundred eyes of 90 patients, scheduled to undergo phacoemulsification surgery, were included. AL and ACD of each patient were calculated preoperatively using IOL Master. Cataracts were classified according toLens Opacities Classification System III (LOCS III) giving nuclear opalescence (NO) grades on slit lamp examination and only patients with grades NO2 and NO3 were included. Eyes were divided into two groups according to ACD and AL: Group-I: ACD 2.0mm – 3 mm and AL 22mm – 23.5mm; Group-II: ACD 3.1 mm -4.0 mm and AL 23.6mm – 25mm. CED measurements were done preoperatively and 2 month postoperatively using specular microscopy. The difference in CED change (Endothelial Cell Loss) between the two groups after surgery was analyzed using SPSS, v 22; IBM Corporation, Armonk, NY.Results:Differences in gender, laterality, age and preoperative CED between two groups were not significant. Difference in postoperative CED was also not significant, however difference in mean change and mean frequency change in CED between two groups was found to be statistically significant.Conclusion:ACD and AL affect the CED during phacoemulsification and Intraocular Lens(IOL) implantation and can be considered as risk factors of peroperative endothelial cell loss.

Correlation between axial length and anterior chamber depth in short eyes, normal eyes, and long eyes

Context Accurate intraocular lens (IOL) power calculation is mandatory to achieve satisfactory refractive outcomes. Axial length, keratometric readings, anterior chamber depth, and other measurements are utilized to estimate postoperative effective lens position. Selecting the formula of IOL calculation depends mainly on axial length (AL) and anterior chamber depth (ACD). Aims To study the correlation between AL and ACD in short, normal, and long eyes. Settings and design The study was conducted at Ain Shams University Hospitals after the approval of the research ethics committee in the Faculty of Medicine, Ain Shams University. Study period: 6 months. Patients and methods The study included 90 eyes of patients presented for IOL or phakic lens implantation. They were divided into three groups according to the AL. Group A included 30 patients with short AL of less than or equal to 22 mm. Group B included 30 patients with normal AL of more than 22 mm and less than 24.50 mm. Group C included 30 patients with long AL of more than or equal to 24.50 mm. The AL and ACD of each patient were measured using The ZEISS IOL Master 500. Statistical analysis used The Statistical Package for the Social Sciences, version 24. Results The results of our study showed that the correlation between the axial length and the anterior chamber depth among short eyes was statistically significant and they were negatively correlated, while no statistically significant correlation existed between AL and ACD in normal and long eyes. Conclusion The AL and ACD are inversely related in short eyes with an AL of less than or equal to 22 mm, while no correlation exists in normal and long eyes with an AL of more than 22 mm.

Comparison of optical biometry versus ultrasound biometry in cases with borderline signal-to-noise ratio.

PurposeTo ascertain if optical biometry determination of axial length (AL) and intraocular lens (IOL) power is significantly different compared to ultrasound (US) biometry in cases with borderline signal-to-noise ratio (SNR).Patients and methodsSixty patients who had cataract and IOL Master biometry with borderline SNR (1.6–2.0) were included. A retrospective chart review was performed to compare data collected with optical biometry and US biometry in cataract cases with borderline SNR.ResultsResults showed that optical biometry IOL and AL measurements were not significantly different from the US measurements. Analysis also demonstrated good agreement between the two methods.ConclusionOur study suggests that, in cases of borderline quality data, IOL power and AL measurements with optical biometry are still useful in surgical planning and that additional US measurements may be used more as a corroborative tool.

Study of distribution of white-to-white corneal diameter and anterior chamber depth in study population obtained with optical biometry using intraocular lens (IOL) master

BackgroundThis study was conducted to measure the distribution of white to white (WTW) corneal diameter and anterior chamber depth (ACD) in the study population by using optical biometry. MethodsIt was a cross-sectional observational study conducted at an Ophthalmology Out Patient Department of a Tertiary Care Centre. Optical biometry was performed in 650 eyes of the 325 patients using IOL Master and WTW and ACD were recorded. Differences in gender, and age-related alterations were analysed statistically. Results195 (60%) subjects were males and 130 (40%) were females. Age of the study population ranged from 13 to 82 years and the mean age was 36.79 years. The mean WTW in the study population was 11.79mm±0.05mm and the mean ACD was 2.74mm±0.03mm. Mean WTW and ACD in male subjects was significantly greater than that of female subjects (p value<0.001). No significant difference in WTW or ACD was seen between the various age groups. No correlation was seen between WTW and ACD in the study population. ConclusionMean WTW and ACD were smaller as compared to other population studies using intraocular lens (IOL) Master. This distribution has paved the way for a population based nomogram for our country which will help us plan surgeries in a better way.